Effect of solvo-thermal treatment temperature on the properties of sol–gel ZrO2–TiO2 mixed oxides as HDS catalyst supports

2006 ◽  
Vol 116 (4) ◽  
pp. 498-504 ◽  
Author(s):  
María C. Barrera ◽  
José Escobar ◽  
José A. de los Reyes ◽  
María A. Cortés ◽  
Margarita Viniegra ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Mixed Oxides ◽  
Sol Gel ◽  
Treatment Temperature ◽  
Catalyst Supports ◽  
Thermal Treatment Temperature

Microstructure and reactivity of small metal particles: The role of Ce additives

1992 ◽  
Vol 50 (1) ◽  
pp. 318-319
Author(s):  
L.D. Schmidt ◽  
K. R. Krause ◽  
J. M. Schwartz ◽  
X. Chu
Keyword(s):  
Atmospheric Pressure ◽  
Noble Metals ◽  
Mixed Oxides ◽  
Catalytic Properties ◽  
Chemical Shifts ◽  
Catalytic Converter ◽  
Structural Evolution ◽  
Single Particles ◽  
Small Metal Particles

The evolution of microstructures of 10- to 100-Å diameter particles of Rh and Pt on SiO2 and Al2O3 following treatment in reducing, oxidizing, and reacting conditions have been characterized by TEM. We are able to transfer particles repeatedly between microscope and a reactor furnace so that the structural evolution of single particles can be examined following treatments in gases at atmospheric pressure. We are especially interested in the role of Ce additives on noble metals such as Pt and Rh. These systems are crucial in the automotive catalytic converter, and rare earths can significantly modify catalytic properties in many reactions. In particular, we are concerned with the oxidation state of Ce and its role in formation of mixed oxides with metals or with the support. For this we employ EELS in TEM, a technique uniquely suited to detect chemical shifts with ∼30Å resolution.

Correction: Small Batch Synthesis of Mixed Oxides of Nitrogen

2020 ◽  
Author(s):  
Philip M. Piper ◽  
Taylor B. Groom ◽  
Jeremy W. Marcum ◽  
Timothee L. Pourpoint
Keyword(s):  
Mixed Oxides ◽  
Oxides Of Nitrogen

In infrared study of sulphated ZrO2-TiO2 mixed oxides

2005 ◽  
Vol 30 (1) ◽  
pp. 49-54 ◽  
Author(s):  
Abdelaziz Sahibed-Dine ◽  
Mhamed Sadiq ◽  
Naima Aderdour ◽  
Mohamed Bensitel
Keyword(s):  
Mixed Oxides ◽  
Infrared Study

Study of nickel-molybdenum catalysts for methanation of carbon monoxide

1980 ◽  
Vol 45 (3) ◽  
pp. 783-790 ◽  
Author(s):  
Petr Taras ◽  
Milan Pospíšil
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Mixed Oxides ◽  
Minor Component ◽  
Fast Neutrons ◽  
Scanning Calorimetry ◽  
Low Concentrations ◽  
Γ Rays ◽  
Molybdenum Catalysts ◽  
Kinetics Of

Catalytic activity of nickel-molybdenum catalysts for methanation of carbon monoxide and hydrogen was studied by means of differential scanning calorimetry. The activity of NiMoOx systems exceeds that of carrier-free nickel if x < 2, and is conditioned by the oxidation degree of molybdenum, changing in dependence on the composition in the region Mo-MoO2. The activity of the catalysts is adversely affected by irradiation by fast neutrons, dose 28.1 Gy, or by γ rays using doses in the region 0.8-52 kGy. The system is most susceptible to irradiation in the region of low concentrations of the minor component (about 1 mol.%). The dependence of changes in catalytic activity of γ-irradiated samples on the dose exhibits a maximum in the range of 2-5 kGy. The changes in catalytic activity are stimulated by the change of reactivity of the starting mixed oxides, leading to different kinetics of their reduction and modification of their adsorption properties. The irradiation of the catalysts results in lowered concentration of the active centres for the methanation reaction.

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